問題詳情
51. In the spring of 2009, scientists recognized a particular strain of flu virus known as H1N1. Thisvirus is actually a ________ of viruses from pigs, birds and humans.
(A) compartment
(B) coordination
(C) combination
(D) combustion
參考答案
答案：[無官方正解]
難度：計算中-1
書單：沒有書單，新增